DEAR BARRY: The home I am buying has a buried fuel tank. This was disclosed by the sellers and their agent weeks after we entered the transaction. At first, they said the tank is made of fiberglass and is only five years old. When my agent and my attorney asked for documentation, the sellers offered to provide it on the day the transaction closes. We asked that it be provided on the day of the final walkthrough, but they did not have the papers on that day. Instead, they admitted that the tank is actually 38 years old and is made of steel. If I cancel the deal now, I could lose my deposit. What can I do? –Maryann